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RFC 1657 - BGP-4 Received Path Attribute Table

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### BGP-4 Received Path Attribute Table

                    bgp4PathAttrEntry OBJECT-TYPE
                        SYNTAX     Bgp4PathAttrEntry
                        MAX-ACCESS not-accessible
                        STATUS     current
                        DESCRIPTION
                                "Information about a path to a network."
                        INDEX { bgp4PathAttrIpAddrPrefix,
                                bgp4PathAttrIpAddrPrefixLen,
                                bgp4PathAttrPeer            }
                        ::= { bgp4PathAttrTable 1 }

                    Bgp4PathAttrEntry ::= SEQUENCE {
                        bgp4PathAttrPeer
                             IpAddress,
                        bgp4PathAttrIpAddrPrefixLen
                             INTEGER,
                        bgp4PathAttrIpAddrPrefix
                             IpAddress,
                        bgp4PathAttrOrigin
                             INTEGER,
                        bgp4PathAttrASPathSegment
                             OCTET STRING,
                        bgp4PathAttrNextHop
                             IpAddress,
                        bgp4PathAttrMultiExitDisc
                             INTEGER,
                        bgp4PathAttrLocalPref
                             INTEGER,
                        bgp4PathAttrAtomicAggregate
                             INTEGER,
                        bgp4PathAttrAggregatorAS
                             INTEGER,
                        bgp4PathAttrAggregatorAddr
                             IpAddress,
                        bgp4PathAttrCalcLocalPref
                             INTEGER,
                        bgp4PathAttrBest
                             INTEGER,
                        bgp4PathAttrUnknown
                             OCTET STRING

                    }

                    bgp4PathAttrPeer OBJECT-TYPE
                        SYNTAX     IpAddress
                        MAX-ACCESS read-only
                        STATUS     current
                        DESCRIPTION
                                "The IP address of the peer where the path
                                information was learned."
                        ::= { bgp4PathAttrEntry 1 }

                    bgp4PathAttrIpAddrPrefixLen OBJECT-TYPE
                        SYNTAX     INTEGER (0..32)
                        MAX-ACCESS read-only
                        STATUS     current
                        DESCRIPTION
                                "Length in bits of the IP address prefix
                                in the Network Layer Reachability
                                Information field."
                        ::= { bgp4PathAttrEntry 2 }

                    bgp4PathAttrIpAddrPrefix OBJECT-TYPE
                        SYNTAX     IpAddress
                        MAX-ACCESS read-only
                        STATUS     current
                        DESCRIPTION
                                "An IP address prefix in the Network Layer
                                Reachability Information field.  This object
                                is an IP address containing the prefix with
                                length specified by
                                bgp4PathAttrIpAddrPrefixLen.
                                Any bits beyond the length specified by
                                bgp4PathAttrIpAddrPrefixLen are zeroed."
                        ::= { bgp4PathAttrEntry 3 }

                    bgp4PathAttrOrigin OBJECT-TYPE
                        SYNTAX     INTEGER {
                                             igp(1),-- networks are interior
                                             egp(2),-- networks learned
                                                    -- via EGP
                                             incomplete(3) -- undetermined
                                           }
                        MAX-ACCESS read-only
                        STATUS     current
                        DESCRIPTION
                                "The ultimate origin of the path
                                information."
                        ::= { bgp4PathAttrEntry 4 }

                    bgp4PathAttrASPathSegment OBJECT-TYPE
                        SYNTAX     OCTET STRING (SIZE (2..255))
                        MAX-ACCESS read-only
                        STATUS     current
                        DESCRIPTION
                                "The sequence of AS path segments.  Each AS
                                path segment is represented by a triple
                                <type, length, value>.

                                The type is a 1-octet field which has two
                                possible values:
                                     1      AS_SET: unordered set of ASs a
                                                 route in the UPDATE
                                                 message has traversed
                                     2      AS_SEQUENCE: ordered set of ASs
                                                 a route in the UPDATE
                                                 message has traversed.

                                The length is a 1-octet field containing the
                                number of ASs in the value field.

                                The value field contains one or more AS
                                numbers, each AS is represented in the octet
                                string as a pair of octets according to the
                                following algorithm:

                                    first-byte-of-pair = ASNumber / 256;
                                    second-byte-of-pair = ASNumber & 255;"
                        ::= { bgp4PathAttrEntry 5 }

                    bgp4PathAttrNextHop OBJECT-TYPE
                        SYNTAX     IpAddress
                        MAX-ACCESS read-only
                        STATUS     current
                        DESCRIPTION
                                "The address of the border router that
                                should be used for the destination
                                network."
                        ::= { bgp4PathAttrEntry 6 }

                    bgp4PathAttrMultiExitDisc OBJECT-TYPE
                        SYNTAX     INTEGER (-1..2147483647)
                        MAX-ACCESS read-only
                        STATUS     current
                        DESCRIPTION
                                "This metric is used to discriminate
                                between multiple exit points to an
                                adjacent autonomous system.  A value of -1
                                indicates the absence of this attribute."
                        ::= { bgp4PathAttrEntry 7 }

                    bgp4PathAttrLocalPref OBJECT-TYPE
                        SYNTAX     INTEGER (-1..2147483647)
                        MAX-ACCESS read-only
                        STATUS     current
                        DESCRIPTION
                                "The originating BGP4 speaker's degree of
                                preference for an advertised route.  A
                                value of -1 indicates the absence of this
                                attribute."
                        ::= { bgp4PathAttrEntry 8 }

                    bgp4PathAttrAtomicAggregate OBJECT-TYPE
                        SYNTAX     INTEGER {
                                       lessSpecificRrouteNotSelected(1),
                                       lessSpecificRouteSelected(2)
                                   }
                        MAX-ACCESS read-only
                        STATUS     current
                        DESCRIPTION
                                "Whether or not the local system has
                                selected a less specific route without
                                selecting a more specific route."
                        ::= { bgp4PathAttrEntry 9 }
                    bgp4PathAttrAggregatorAS OBJECT-TYPE
                        SYNTAX     INTEGER (0..65535)
                        MAX-ACCESS read-only
                        STATUS     current
                        DESCRIPTION
                                "The AS number of the last BGP4 speaker that
                                performed route aggregation.  A value of
                                zero (0) indicates the absence of this
                                attribute."
                        ::= { bgp4PathAttrEntry 10 }

                    bgp4PathAttrAggregatorAddr OBJECT-TYPE
                        SYNTAX     IpAddress
                        MAX-ACCESS read-only
                        STATUS     current
                        DESCRIPTION
                                "The IP address of the last BGP4 speaker
                                that performed route aggregation.  A value
                                of 0.0.0.0 indicates the absence of this
                                attribute."
                        ::= { bgp4PathAttrEntry 11 }

                    bgp4PathAttrCalcLocalPref OBJECT-TYPE
                        SYNTAX     INTEGER (-1..2147483647)
                        MAX-ACCESS read-only
                        STATUS     current
                        DESCRIPTION
                                "The degree of preference calculated by the
                                receiving BGP4 speaker for an advertised
                                route.  A value of -1 indicates the
                                absence of this attribute."
                        ::= { bgp4PathAttrEntry 12 }

                    bgp4PathAttrBest OBJECT-TYPE
                        SYNTAX     INTEGER {
                                       false(1),-- not chosen as best route
                                       true(2) -- chosen as best route
                                   }
                        MAX-ACCESS read-only
                        STATUS     current
                        DESCRIPTION
                                "An indication of whether or not this route
                                was chosen as the best BGP4 route."
                        ::= { bgp4PathAttrEntry 13 }

                   bgp4PathAttrUnknown OBJECT-TYPE
                        SYNTAX     OCTET STRING (SIZE(0..255))
                        MAX-ACCESS read-only
                        STATUS     current
                        DESCRIPTION
                                "One or more path attributes not understood
                                 by this BGP4 speaker.  Size zero (0)
                                 indicates the absence of such
                                 attribute(s).  Octets beyond the maximum
                                 size, if any, are not recorded by this
                                 object."
                        ::= { bgp4PathAttrEntry 14 }

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RFC 1657 - BGP-4 Received Path Attribute Table